Xyris hymenachne

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Xyris hymenachne


Solitary to cespitose, often sub-bulbous, slender, smooth perennial, 20-60 cm high, stem contracted. Leaves in a fan or ascending, 5-20 cm, sheath entire to sparsely ciliate at base, dull brown or stramineous, eligulate, blade flattened, 1.5-4 mm wide, margins thin or slightly thickened, smooth to ciliolate, surface smooth to papillose-rugulose. Scapes distally subterete, uni-multicostate, ribs smoothto papillose or ciliolate; spikes obovoid to subglobose, 5-8 mm, pale dull brown, bracts in a spiral, with convex, papillose back and no dorsal area, with broad, pale, scario-lacerate borders,empty bracts 2-4, slightly shorter than the flowering ones, these obovate to broadly oblong, 7-8 mm. Lateral sepals free, inequilateral, curved, 4-6 mm, keel ciliate or fimbria-ciliate from middle to apex; petals obovate, ca. 5 mm; staminodes bearded; anthers ca. 1.5 mm. Capsule ca. 4 mm, placentation basal, valves eseptate; seeds cylindric-fusiform or ellipsoid, 0.6-0.7 mm, amber.


Andes present, Guyana present, Mt. Roraima present, SE Brazil present, SE Colombia present, Southern America: Brazil South (Santa Catarina present)
SE ColombiaE to Mt. Roraima, Guyana, and in BrazilE of the Andes S to Santa Catarina, SE Brazil.


This species is at once distinctive because of the broad, pale, scarious bract borders, but is otherwise extremely variable as to habit, vestiture and pigmentation. In short, because of its wide geographic and morphological expression it is a "matrix" species, bordering on X. jusca A. Nilsson of southern Brazil, and X. concinna N.E. Br., X. thysanolepis Maguire & L.B. Smith of northern South America.